Hi All

So to up date progress with this radio. Through the week I wire-brushed the chassis with a small rotary tool! It took off the surface rust.

I then taped up all items and rust converted all of the chassis and speaker. Looks a mess in the photo but its not a big deal.

I then lightly sanded the chassis and speaker with some fine grade (0000) steel wool to smooth out any rough areas.

Then applied a coat of the "step 2" Wattle spray Primer. This stuff sticks to anything! Tip for speakers, I used a small amount of crush paper between the cone and the speaker frame. if you take your time on this step you will not get any paint on the cone and that is important!

Once dry (24hrs) I cleaned it up and gave the whole unit a coat of Grey "Top Coat Hammer Finish". This paint says that you don't have to do any surface prep but I would still do the prep as I have because the finish looks great as shown in the pictures.

All that is left to paint is the black on the transformer and the speaker magnet (Magnet shows the primer still) and put some brown craft paint on the winding card for the transformer.

Mullard 1110 Circuit Diagram
Mullard 1110 Parts List

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Valve radios, They just don't make them like they used to

Hi All

Its been a while since I got a chance to work on this radio but here is the update.

It finally works! It has taken me a while to sort out. I had some wiring to sort out and when looking closer it is painfully evident that someone has been there before me. (Sound Familiar Marcc?)

Once all electros were replaced, I re stuffed the main chassis cans, and replaced the dial globe cable and placed a temp power cable and a couple of resistors (R22 and R13) in the HT line that were O/C.

A very quick check with just the rectifier Valve in (6V4 not the 6X5GT as described in the parts) the HT was sitting at about 270 ish volts, and concluded that this was ok.

The output valve 6M5 and the 2nd 6N8 was installed to test it the audio stage was alive doing the "Blurt" test on the grid of the 6N8 from the vol control, a healthy or so I thought, noise was heard from the speaker.

Encouraged by this I went on and put in the Frequency Converter (6AN7) and the IF amp (1st 6N8). Now I had something but couldn't tune in any stations. I had a look at the voltages on the 6AN7 and found that the voltages on the Plate and screen seemed ok and I moved on. This was my first mistake! A experienced restorer or tech will know exactly what I missed, More on this later!

So scratching my head as to why it wasn't working I grabbed the SIg Gen and started sweeping with a loose coupling to the ant lead. Hmm... I could hear the sig gen sweeps so what was going on! sitting back for a while I thought about it and set the sig gen at roughly 455kHz to see if I could tune something in, this let ABC national (A very very strong signal in my area) be tuned at a few places on the dial.

At this stage I put the set aside for a few days due to family and work commitments. I started to think about this set again last week and got a replacement gang as I knew the one I had was stuffed and has a short with the gang all the way in the closed position. With this changed then I started looking at the converter valve again. I started checking voltages again and got about the same as before, except this time I checked the Osc section (What I forgot to test from the first time) and found that its voltage was well off. The voltage drop over R3 was about nothing so I suspected the valve was stuffed. I did a swap of it with one I had in another radio and the set sprung? into life. When I say life it sounded distorted and suffered from a frequency instability when prodding around C10 (100pF).

I pulled this out of cct and tested it on my meter. With my finger moving closer to the device under test it changed it Capacitance by a large amount (Went up by about 30pF). This was changed out and the set was stable but distorted.

Now for the audio distortion. I started chasing the audio path. I went straight to C21 (0.02uF) and found that this was replaced by a 0.01μF so changed it out. Turning on again most of the distortion was gone but still didnt sound right. Checking connections to and from the 2 audio valves I couldn't find C16 (0.02uF) bypass. I put in a temp and this fixed up the audio to be clear and powerful!

So the take away from this is, if someone has been at it before you take everything as wrong!

Below is the photo of the set on the bench using my method of a test stand. Very simple setup!

Another Update:

I have had the set on test for about 24hrs and noticed that the sensitivity of it varied from time to time. I started the "Technical Tap" method just to see if that changed things. it showed around the IF cans and the 1st 6N8 that the sensitivity improved. I stated to isolate things by changing the 6N8 and found this when put on the tester varied its gain when tapped. So all up in this set I have changed 2 valves due to internal faults inside them. I guess after 50 odd years being bounced around from time to time the internal elements and connections weaken.

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Valve radios, They just don't make them like they used to

Hi All

I have finally finished the radio. Since it was going to be thrown out because it was “just another Philips with a cracked cabinet”, it has come up looking very good in my opinion.

Dan

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Valve radios, They just don't make them like they used to

The hammer finish paint really comes up a treat! Good job

You may actually be able to glue some awning cloth under the crack to hold it. A lot of that stuff is designed to be in the sun so will handle a bit of heat. On most cabinets I pad Araldite (not 5min) into the cloth before placing it onto the well cleaned surface.

People lifting the cabinet by the top are the chief cause of that sort of crack.

Set looks good. From reports 6N8 is not a particularly reliable valve.

Marc

Dan,
I still have a perfectly good cabinet here.
You can have it for the postage if I can get it to you in one piece.

Baz

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Baz

VK6MU

Hi

I intend to leave the radio this way. there is a small wooden paddle pop stick glued to under the crack.

As for the other cabinet I will give it a miss, Chances are that it will get broken in transport,

I have gone through my stocks of 6N8s and found a few that are bad. I have also found another Philips 172 that had a 6N8 that was doing the same. I had put it to the back of my collection with a note to check the Micas when I had a free min.

Dan

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Valve radios, They just don't make them like they used to

This looks identical internally to the 1950 Philips Radioplayer 123, only visible difference the dial glass and the grille (123 is vertical). I didn't notice pick-up terminals on the back, though.

I think Mullard sets were popular in UK after the war - perhaps ex-service people were familiar with the brand and some considered it more "English" than Philips. Designs a little more dowdy, which perhaps also appealed to the Poms. Like British cars of the period.

Maven

The cabinet of the 123L I sent in (1st page) is identical

Marc